Reflector lamp

ABSTRACT

The invention relates to a reflector lamp ( 1 ) with a reflector ( 2 ), with a lamp base ( 3 ), with a halogen burner ( 4 ), and with a cap ( 6 ) which envelops the halogen burner ( 4 ) at least partly and is retained by a bracket ( 7 ) which extends as a bridge from one reflector side to the other. According to the invention, the halogen burner ( 4 ) is surrounded by a glass bulb ( 5 ).

The invention relates to a reflector lamp with a reflector, with a lampbase, with a halogen burner, and with a cap which envelops the halogenburner at least partly and is retained by a bracket which extends as abridge from one side of the reflector to the other.

Such a reflector lamp is known from U.S. Pat. No. 4,623,815. The lampcomprises a halogen burner in the form of a halogen incandescent lampwhich is arranged on a lamp base and whose lamp bulb is enveloped by acap.

If such a reflector lamp is inexpertly introduced into a holder, thehalogen burner may be damaged such that lamp life is shortened.

The invention has for its object to improve a lamp such that damageduring insertion is prevented.

This object is achieved by the characterizing feature of claim 1.According to the invention, the halogen burner is enveloped by a glassbulb. The halogen burner is arranged in the interior of said bulb and isthus protected. A direct access to the halogen burner is preventedthereby. Contacts and electrically conducting connection wires are notdestroyed during insertion.

Advantageously, the glass bulb has a reflection layer. Light rays arereflected back to the reflector thereby, and an axial light radiation isenhanced. This improves a light emission characteristic and counteractsstray light.

In a simple manner, the glass bulb has a layer that is impermeable tolight. Glare is prevented thereby.

Advantageously, the bottom of the glass bulb has an opening. Heat canescape from the bulb in this manner.

Advantageously, the lamp base has a cylindrical opening with a step intowhich the glass bulb can be inserted. The glass bulb is thus given adefined position both in radial and in axial direction.

Advantageously, the lamp base has a spring. The spring presses the glassbulb against an inner cylinder surface of the lamp base, so that theglass bulb is retained in particular in a second axial direction.

Advantageously, the glass bulb comprises a bulge. The reflector has anopening bounded by a reflector edge in its top portion. If this edgeprojects over or into the opening of the lamp base, and thus over thebulge of the glass bulb, the reflector will serve as a retaining meanswhich defines the position of the bulb in the second axial direction.

Advantageously, the glass bulb and the cap are at a distance from oneanother. Heat may thus escape from the bulb and the cap, and a heataccumulation is avoided. A temperature balance of the lamp is improvedthereby.

Advantageously, a spring is arranged between the glass bulb and the cap.The spring presses the glass bulb onto the step of the opening. Theglass bulb is thus given a defined position in the second axialdirection, and a secure seat is safeguarded for the bulb.

Advantageously, the glass bulb is at least partly surrounded by the cap.The glass bulb is given a defined position in the second axial directionthereby, and a secure retention of the glass bulb is safeguarded.

Advantageously, the halogen burner, also denoted two-pinch burner below,has two mutually opposed pinches. The two-punch burner has anellipsoidal glass bulb with an optimized light emission characteristic.

Advantageously, the electrical return lead comprises a locking means.The glass bulb is retained in the second axial direction thereby, and areliable retention of the glass bulb is safeguarded.

Advantageously, a bulb of the halogen burner has an IR coating. Thecoating reflects infrared radiation back onto the coil and thus improvesan energy balance of the halogen burner.

Embodiments will now be explained in more detail below with reference tothe drawing for a better understanding of the invention. In the drawing:

FIG. 1 is a diagrammatic picture of a reflector lamp,

FIG. 2 shows a glass bulb held in a lamp base by a reflector edge inlateral sectional view,

FIG. 3 shows a glass bulb in lateral sectional view, and

FIG. 4 shows a second reflector lamp in lateral sectional view.

FIGS. 1 and 2 show a reflector lamp 1 with a reflector 2, a ceramic lampbase 3, a halogen burner 4, a glass bulb 5, and a cap 6 which envelopsthe halogen burner 4 at least partly and is retained by a bracket 7which extends in the form of a bridge from one side of the reflector tothe other. The cap 6 and the bracket 7 are constructed as an integralcomponent. The reflector 2 is held by the lamp base 3. The lamp base 3has a tubular basic body 8 with a disc-shaped extension 9. Inside thetubular basic body 8, a first cylindrical opening 10 with a largerdiameter 11 extends up to a step 12 and a second cylindrical opening 13of smaller diameter 4. The glass bulb 5 has a cullet 16 at a first end15. The glass bulb 5 is inserted with its cullet 16 into the opening 10with radial clearance such that an end face 17 of the glass bulb 5 abutsthe step 12. The reflector 2 extends with an inner reflector edge 15over the cullet 16 of the glass bulb 15 so that the glass bulb 15 isheld in the opening 10 of the lamp base 3. The bulb 5 has a bottom 21with an opening 22 at its second end 20. The halogen burner 4 has anellipsoidal glass body 23 with two mutually opposed pinched ends 24 and25 which are traversed by respective electrical conductors 26 and 27.The end 24 projects through the opening 22 of the bottom 21 and into thecap 6. The glass body 23 is positioned in a focus of the reflector 2.The electrically conductive connection 27 extends inside the glass bulb5 to an electrical contact 28 of which one part 29 is arranged below thelamp base 3. The electrically conductive connection 26 extends to anelectrical return lead 30 which lies along the glass body 23 and leadsto an electrical contact 31. The electrically conductive connections 26and 27 lead to a coil 32 in the interior of the halogen burner 4. Theellipsoidal glass body 23, the coil 32, the cap 5, and the glass bulb 5share a common longitudinal axis 33.

To obtain a good illumination, the lamp 1 should radiate lightsubstantially within a defined angular region between the axialdirection 34 and an azimuth angle 36. The lamp 1, however, also radiateslight into a lateral region 35. This lateral region 35 illuminates aspace which is defined by the azimuth angle 36 and a further azimuthangle 37. The azimuth angles 36 and 37 are defined by an outer reflectoredge 38 and a cap edge 39. To deflect this light, which is denoted straylight, and to utilize it within a region between the axial direction 34and the azimuth angle 36, the bottom 21 of the glass bulb 5 has areflection layer 40. The reflection layer 40 reflects light onto thereflector 2, whereby the stray light in the region between the axialdirection 34 and the azimuth angle 36 is deflected.

FIG. 3 shows the glass bulb 5 with the bottom 21, the opening 22, andthe reflection layer 40 whose dimension is given by the azimuth angles36 and 37. The reflection coating 40 reflects stray light back onto thereflector 2. Alternatively, the coating 40 may be formed as a layerimpermeable to light.

FIG. 4 shows a reflector lamp 51 with a reflector 52, a ceramic lampbase 53, a halogen burner 54, a glass bulb 55, and a cap 56 whichsurrounds the halogen burner 54 at least partly and is retained by abracket 57 which extends as a bridge from one side of the reflector tothe other. The cap 56 and the bracket 57 are constructed as one integralcomponent. The glass bulb 55 is inserted with an open end 58 into anopening 59 of the lamp base 53 such that its position is defined both ina radial direction 60 and in a first axial direction 61. The reflector52 is retained by the lamp base 53. For this purpose, the reflector 52has three projections 62 which extend into openings 63 of the lamp base53 and are fastened therein by clamping, locking, or bending. The cap 56envelops the glass bulb 55 and defines its position also in the radialdirection 60. The cap 56 has an inwardly directed bulge 64 which retainsthe bulb 55 in a second axial direction 65.

1. A reflector lamp (1, 51) with a reflector (2, 52), with a lamp base(3, 53), with a halogen burner (4, 45), and with a cap (6, 56) whichenvelops the halogen burner (4, 54) at least partly and is retained by abracket (7, 57) which extends as a bridge from one side of the reflectorto the other, characterized in that the halogen burner (4, 54) isenveloped by a glass bulb (5, 55).
 2. A reflector lamp as claimed inclaim 1, characterized in that the glass bulb (5, 55) has a reflectionlayer (40).
 3. A reflector lamp as claimed in claim 1, characterized inthat the glass bulb (5, 55) has a layer (40) which is impermeable tolight.
 4. A reflector lamp as claimed in one or several of the precedingclaims 1 to 3, characterized in that a bottom (21) of the glass bulb (5,55) has an opening (22).
 5. A reflector lamp as claimed in claim 1,characterized in that the lamp base (3, 53) has a cylindrical opening(10, 13, 59) with a step (12).
 6. A reflector lamp as claimed in claim5, characterized in that the lamp base (3, 53) comprises a spring.
 7. Areflector lamp as claimed in one or several of the preceding claims 1 to4, characterized in that the glass bulb (5, 55) comprises a bulge (16).8. A reflector lamp as claimed in one or several of the preceding claims1 to 4 and 7, characterized in that the glass bulb (5, 55) and the cap(6, 56) are at a distance from one another.
 9. A reflector lamp asclaimed in claim 8, characterized in that a spring is arranged betweenthe glass bulb (5, 55) and the cap (6, 56).
 10. A reflector lamp asclaimed in one or several of the preceding claims 1 to 4 and 7 to 9,characterized in that the glass bulb (5, 55) is at least partlysurrounded by the cap (6, 56).
 11. A reflector lamp as claimed in claim1, characterized in that the halogen burner (4, 54) comprises twomutually opposed pinched ends (24, 25).
 12. A reflector lamp as claimedin claim 11, characterized in that an electrical return lead (30) of thehalogen burner (4, 54) comprises a locking means.
 13. A reflector lampas claimed in claim 1 and/or 11, characterized in that the halogenburner (4, 54) has an IR coating.